So our Mass goes back, without essential change, to the age when it first developed out of the oldest liturgy of all. It is still redolent of that liturgy, of the days when Cæsar ruled the world and thought he could stamp out the faith of Christ, when our fathers met together before dawn and sang a hymn to Christ as to a God. The final result of our enquiry is that, in spite of unsolved problems, in spite of later changes, there is not in Christendom another rite so venerable as ours. ~Fortescue

"Nuns working"... Working indeed, but no nuns. It is a picture of the beguinage of Ghent. These beguines weren't nuns, but unmarried women willing to live a religious live, but without any vows. They could leave the beguinage at any moment for a live in the world. Nowerdays, there is only one beguin in Flanders (Belgium), the last one of this medieval religious institution in the Netherlands.